Electric stove



Nov. 15, 1949 R. BoRzA ET AL 2,488,264

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ELECTRIC STOVE Filed April 9, 1948 v 3 Sheets-Sheet 3 E INVENTORS gf/ 35m2/4 J Mx. JWM. o (J4 TTOAZE'Y.'

Patented Nov. 15, 1949 UNITED STATES PATENT OFFICE ELECTRIC STOVE Raphael Borza and yHelen L. Borza, Yonkers, N. Y.

Application April 9, 1948, Serial No. 20,026

This invention relates to electric stoves or ing adjustable time-delay circuit opening means whereby the power is `automatically .turned off at a predetermined time, so that a person may attend to other matters while the food is being cooked with the assurance that it will be cooked for exactly the desired length of time without danger of overor under-cooking.

The above broad object, as well as additional and more specic objects, will become apparent in the following description, wherein characters of reference refer to like-numbered parts in the accompanying drawings. It is to be noted that the drawings are intended for the purpose of illustration only, and that it is neither desired nor intended to limit the invention necessarily to any or all of the exact details of construction shown except insofar as they may be deemed essential to the invention.

Referring briefly to the drawings,

Fig. 1 is a perspective view of an electric stove illustrating one application or embodiment of the invention.

Fig. 2is a side elevational View of the same.

Fig. 3 is a front elevational view of the same.

Fig. 4 is a plan view of the saine..

Fig. 5 is a sectional view taken on the line 5 5 of Fig. 4.

Fig. 6 is a sectional view taken on the line 6--6 of Fig. 2, showing the time-delay switch in open position. n

Fig. 7 is a view similar to Fig. 6, showing the time-delay switch in closed position.

. Fig. 8 is a sectional view taken on therline 8--8' of Fig. 3.

, Fig. 9 is a vertical longitudinal sectional view through the pneumatic cylinder of theY timedelay means. v

Fig. 10 is a sectional view taken on the line Ill-IU of Fig. 6. y

Fig. l1 is a wiring diagram of the stove including the heating elements of both burners and the oven. y y

Fig. 12 is a sectional View taken on the line I2-I2 of Fig. 7.

Fig. 13 is a fragmentary perspective view of the lower end of the slide forming part ofthe .time-delay switch operating mechanism.

Fig. 14 is a fragmentary perspective View of another detail of the said mechanism.

Referring in detail to the drawings, the nu- Ymeralk I0 indicates the housing orV casing of the stove, lwhich includes the bottom I I from rwhich 3 Claims. (Cl. 161-1) four posts I2 rise. The latter support the front wall I3, side wallsld, and the rear wall I5. The floor I I extends rearward of the rear wall I3, and a rearwardly extending extension casing or cover I6 is provided to conceal the time-delay switch mechanism described below. lA roof or top member I1 is removably secured, as by means of screws I8, to the posts I2.

Opposed inner side walls I9 provide inner frame members to support the heating elements and other interior parts as will be claried below. The walls I9 are provided with aligned deformations 20 which provide guides and supports for a drawer 2| adapted lto be drawn through a suitable opening in the front wall I3.

Supported horizontally between the members I9, in vertically spaced relationship as shown in Fig. 5, are plates or sheets of asbestos 22 having mounted on their opposed sides plates 23 of suitable insulating material such as porcelain. The latter are provided with suitable spaced fixed bobbins 24 on which the oven heating element 25 is wound, and between which the drawer 2| lies when closed. A layer 2B of asbestos is also provided behind the front wall of the drawer 2|.

Two burner elements, 21 and 28, are provided in the top of the stove, either of which, for eX- ample burner 28, is directly connected through its standard switch 29 across the electrical supply lines 30. The other burner 21, together with the oven element 25, is connected to the supply lines 30 through their respective standard switches 3| and 32 and the time-delay switch described below. A horizontal cross member 33 between the side members I9 supports the burners 21 and 28.

Mounted horizontally against the back wall I5 is a cylinder 34 in which a piston 35, with its rod 35, is slidable. The end 31 of the cylinder is closed, but at that end the cylinder is provided with a standard needle valve 38 manipulated by its screw 39 so that the rate at which air may enter or escape from the cylinder is under control.

A T-shaped collar, having a circular opening therethrough to accommodate the rod 36 slid.- ably therein, is shown at 40, and is locked by means of a screw 4I on the rod 36 in a position intermediate the length of the rod. A link 42 has one end rolled into a sleeve 43 which, by means of a screw 44 threaded into one side of the base of the collar 40, pivotally secures that end of the link 42 to the collar 40. On its free end the link 42 has a hook-like attachment or extension 45 extending outward (with respect to the rear wall I). An upright support 45 is secured against the rear wall I5, and pivoted at its bght thereto is an L-shaped lever 41 having the long arm 48 and the short arm 49. The arm 48 is positioned between the link 42 and the wall l5, and the hook 45 extends downward over the arm 41 so that the arm 41 is coniined between the hook 45 and the wall I5. A switch lever 50 has one end pivoted at 5I to the wall I5 and passes between the upright 4E Iand the wall I5, terminating in a concave tip 52. A roller 53, or pulley` is mounted between the upper end of the upright 4B and the wall I5. A flexible cable 54 of any suitable material is trained about the pulley 53, having one end secured to the iront end of the link 42 and the other end secured to the switch lever El! near the forward end thereof.

An L-shaped slide 55 has its long arm 56 provided with spaced vertical slots 51, and by means of screws 5B is slidably mounted against the upright 45. One upper corner of the slide 55 is cut away to leave a projecting tongue 59 and a shoulder 50, the upper surface 5l of the tongue sloping as shown.

When the lever 5B is in the normal raised position shown in Fig. 6, the the lever 41 is nearly horizontal and the arm 49 thereof registers in the corner cut-out of the slide 55. The arm 49 is rounded to form a nose, as shown, the tip of which is adapted to slide on the sloping surface 5I of the tongue 59. Pin-like projections 62 and 53 are provided on the arm 49 of the lever 41 and on the slide 55. and these are connected by a coiled spring $4 normally urging the slide 55 upward normally urging the lever 41 to turn clockwise (Figs. 6 and '1).

A block B5 oi insulating material is attached to the short arm 55 of the slide 55 and extends inward toward the wall I5 and its edge lies in the path of the descending lever 59; thus, in movement of the lever :19 through the arc between the positions shown in Figs. 6 and '1, the lever carries the slide downward the distance between the positions shown in those figures. An. insulating block 51 is secured to the wall I5 and is provided with two electric contacts 68 and 69. A metallic button 19 rigid on the end of the block 65 is thus brought down from the position shown in Fig. 6 to that shown in Fig. '1 in which it bridges and closes the circuit between the contacts 58 and 69.

The piston 35 is normally in a position toward the left of its cylinder 34 (Fig. 9). Upon depressing the lever 50 from its upper to its lower eX- treme positions, it is apparent that the cable 54 will pull out the rod 3E and move the piston 35 to the right, thereby creating a suction in the cylinder tending to restore the piston to its original position` As the hook l5 on the link 4i. thus moves to the right, it permits the lever 41 to rotate clockwise owing to the spring 54, and when the lever 59 has depressed the block 56 the slide 55 will have been lowered to close the contacts 68, 59 and also to lower the tongue 59 out of contact with the nose 49 whence the lever 41 swings into the position shown in Fig. '1 wherein the nose 49 prevents raising or the slide 55 by the spring B4. When the lever 59, in the position shown in Fig. '1, is released, the suction in the cylinder 34 will gradually draw the rod inward, whence the hook moving leitward, will `gradually swing the lever 41 counter-clockwise and at the same time, because of the cable 54, raise the lever 50, the nose 49 during this time riding down the sloping end surface 5I ci the tongue 59. When the nose 49 has ridden oil the surface 6I, the spring 64 is free to snap the slide upward, thus opening the circuit through the contacts 58, 59 and restoring the lever 50 and the lever 41 to their original positions shown in Fig. 6.

The electrical connections and circuits are shown in 1l, the lines 39 leading to terminal blocks 1I and 12. It is to be noted that the burner 21 is put into use by closing the switch 3 I, and the oven elements 33 are in use when the switch 32 is closed, in both cases the circuits being through the time-delay switch shown fragmentarily in the wiring diagram at 56, 53, B9, and 1E. By closing both switches 3l and 32, both the oven and burner 21 are in use simultaneously with the time-delay switch. A terminal block for connecting various leads on the stove is shown at 13, but for the sake of simplicity the leads have been omitted from the drawing excepting in the wiring diagram.

The following means is provided for controlling the length of time that the switch 69, 69, 10 is to remain closed. A plate 15 is secured to the wall I5, and an L-shaped bracket 14 is integral therewith. A pin 11 has its lower end passing freely through an opening in the horizontal arm 16 oi this bracket, and is provided with an enlarged, large-pitch screw thread 18 which is engaged by the end of a screw 19 which passes through the vertical arm @il of the bracket. A knob 8| on the upper end of the stem 11 serves as a handle to turn the stem, and it is provided with an index mark 32 to be used in conjunction with a graduated dial 83 on the cover I1. lt is obvious from Fig, 6 that turning the stem 11 so as to cause it to descend will reduce the time interval during which the said switch is closed, for the tip of the stem forces the link 42 to approach closer to the horizontal position, and the hook end of the link likewise swings the lever 41 closer toward horizontal position, and the closed toward horizontal position that the lever 41 is, the nearer toward the end of the surface 5I of the tongue 59 is the nose 49, whence the latter requires a lesser time to ride off the nose. Reverse rotation of the stem 11 will increase the length of the said time interval.

It is apparent from the above that a practical and useful electric stove having controlled timedelay circuit-opening means in connection with both a burner unit and an oven heating element, has been provided, whereby cooking is substantially simplified.

Obviously, modifications in form and structure may be made without departing from the spirit or scope of the invention.

We claim:

1. Time delay switch closing means for an electric stove comprising a cylinder having a piston slidable therein and having the piston rod of said piston slidable through one end of the cylinder whereby withdrawal of said rod from the cylinder creates a suction in the cylinder tending to restore the rod into the cylinder, a key having one end pivoted to the stove and having the other end free and adapted to be depressed below the level of said rod, a pulley rotatably mounted on the stove above the level of of said rod, a link pivoted at one end to said rod intermediate the length of said rod, an L-shaped 5 lever pivotally mounted at its bight to the stove at a point above the lever of said rod, said level` having a long arm extending approximately horizontally, said link having a hook on its free end slidably engaging said long arm of said lever, the other arm of said lever being relatively short, a vertical slide slidably mounted on the stove in the plane of said lever, generally below said short arm, resilient means normally urging said slide upward and normally urging said lever to swing said short arm against said slide, said slide having a projection thereon engageable by said key during depression of said key to lower said slide, a cable trained about said pulley and having one end secured to said free end of said link and the other end secured to said key intermediate the length of the key for pulling said rod outward from said cylinder upon depression of said key, said resilient means in the lowermost position of said key swinging said short arm over the top of said slide and thereby serving as a stop to prevent rising of said slide, said suction upon release of said key slowly restoring said rod into said cylinder and consequently swinging said lever in the reverse direction and causing said fill 2. The device set forth in claim 1, having means for varying the time interval between the depression of said key to said lowermost position and the instant at which said short arm rides off the top of said slide as aforesaid.

3. The device set forth in claim 1, having means for varying the interval of time between the depression of said key to said lowermost position and the instant at which said short arm rides off the top of said slide as aforesaid, said means comprising a pin mounted on the stove substantially at right angles to said rod and spaced therefrom, said link in the normal indrawn position of said rod lying between said pin and said rod and in contact with said pin, said pin having threads thereon for advancing or retarding the same to swing said link toward said rod or permit said lever to swing said link away irom said rod thereby respectively decreasing or increasing said time interval.

RAPHAEL BORZA. HELEN L. BORZA.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS- Number Name Date 1,491,591 Edwards Apr. 22, 1924 1,959,935 Shroyer May 22, 1934 2,005,253 Braun June 18, 1935 2,251,925 Edmunds et al Aug. 12, 1941 2,343,347 Turner Mar. '7, 1944 

